...when people have an unsatisfactory experience, venting is a big motivator to engage in negative word of mouth.
Netsafe says it is hearing of more cases where disgruntled people are attacking judges and other public officials through social media - and the attacks are getting a harder edge.
Lang says the same trend is happening with brand communication, with reactions against brands now swifter and more fierce. There were limited options for stopping the attacks getting out of hand, he said.
Often the best option is to deal with unhappy tweeters or Facebook users offline.
But some were more interested in laying out gripes than having them resolved.
"We know from research that when people have an unsatisfactory experience, venting is a big motivator to engage in negative word of mouth.
It was only so much about things being put right and more about sharing their "disgruntledness", he said.
That is apparent as soon as you ask someone to donate to something - the reaction disappears very quickly.
Increasing numbers of people using social media like Twitter meant numbers of unhappy comments could grow rapidly to a groundswell which became hard for people to disagree with.
The Twitter campaign that led to an advertiser boycott of the Willie and JT show because of an unpopular interview was a case in point.
"Once a few people said they were unhappy with the offending interview others agreed even thought they never listened to it at all."
Negative social media campaigns could frighten businesses, but often they were superficial.
"That is apparent as soon as you ask someone to donate to something - the reaction disappears very quickly," he said.